43gl when should fuel pump come on

"please help

4-3gl (430

"please help

4-3gl (430b V6) 1994 carb tybe

I have now since buying the boat over 3 years ago had a weid problem, which i originaly thought was not a fault.

When starting the engine the fuel pump comes on before the engine at postion 2 of the key switch (position 3 is starting or cranking)

I have thought over the years this is normal, but after talking to a dealer recently it turns out this is wrong and the fuel pump should come on while cranking and remain on while engine is running.until killed by switch or dead mans switch.

For several months now i have traced the circuit diagrame and notice the fuel pump is connected with the starting loom to solind and auto choke on carb, on a yellow wire.

For some weird reasion the purple wire that runs from ignition side on engine(coil) and runs up to the dials is the wire that control the fuel pump under dash board. but the circuit diagrame shown nothing is linked between fuel pump and purple wire its a seperate side of loom.

All relays have been checked, i have metered the loom including continuty checking, i can not find out what is causeing it or even now were to look, i am at a complete stop.

any help or ideas would be realy appreciated or is this normal and just dont worry about it,
the fuel pump cuts of normaly by switch.
what do you think"

"Mark, the fuel pump is energi

"Mark, the fuel pump is energized from a signal coming from the alternator while running, and from the ignition switch (S terminal) during the engine start-up. Each of the lines (green wire from alternator, yellow/red from start) has a diode to prevent back-feeding.

The power supply to the fuel pump, however, comes from the starter large post.

Check the Seloc manual, page 7-44. The diagram on that page should be self-explanatory."

would the seloc manual be any

would the seloc manual be any different to the v/p manual i have

the other thing el Pescador th

the other thing el Pescador there is only one diode in my engine loom and that is to stop back emf from alternator there is no other diode in the loom anywhere.

does that make sense

"looking at the circuit diagra

"looking at the circuit diagrame the fuel pump is connected via a yellow wire from choke to fuel pump and a T off through the relay terminal 87 the loom continues from the T off to the P on back of starter solinod, that is it no other connection other than ground/negative.

the red/yellow on switch S has a 8 amp fuse then on to newtral position switch then on to main block connector and in to engine loom and there is a symbol which just says connector.

this is from my manual"

"The other thing i have added

"The other thing i have added is the newtral switch, which was brocken when i had it, when the lever is in newtral it should of pushed a switch in. on the yellow and red and yellow.

i went and purchased a push in/out marine switch positioned right along side the lever so for me to push the switch in the lever has to be in newtral position once the engine has started and is running the switch is released."

"Mark, I don't have the OE

"Mark, I don't have the OEM manual, but I suspect that's where Seloc gets the information from. In any case, if there was no diode in the yellow/red wire going to the (S) in the ignition switch, guess what would happen to the starter solenoid once the alternator is sending its signal to the fuel pump relay.

This, of course, assuming that Seloc's diagram depicts your actual installation. Could you upload a picture of your diagram or e-mail me a copy so that I can have a look? Thanks."

El pescador

have just sent

El pescador

have just sent email with a few attachments.

mark

"Greetings, Mark.

I have lo

"Greetings, Mark.

I have looked at the drawings you sent me. If your engine is wired the way the drawing states, then the pump will start at the same time you turn the key to the (i) position, as the relay 28 becomes energized. The relay's coil pins are 86 and 85: 85 goes to ground and 86 to the ignition switch (i) position. Once the relay's coil becomes energized, the contact between 30 and 87 will close, and power will reach the fuel pump and the electric choke from the automatic fuse (20). What will happen once you move the ignition key to start (s) position, a signal will be sent to terminal 86 on relay 29 (starting relay), the contact between 30 and 87 will close on that relay, and power will reach the terminal S on the starter solenoid. However, while the engine cranks, the battery voltage will drop and the signal to the relay 28 could be too weak due to the resistor 27, to the point that the relay may temporarily become de-energized, in which case the fuel pump and the choke would not be powered. To prevent that from happening, both the fuel pump and the choke will be energized during the starting process from the contact P on the starter solenoid, which is only energized while the starter is cranking.

The above are my conclusions after rading the drawing.

Clear as mud? Sorry for the low definition picture, but the forum program STILL does not allow pictures over 100 Kb.

"

"Thank you very much you are a

"Thank you very much you are a gem for looking.

I have been out on boat today testing the circuits around the relay and useing a jumper lead across the relay block trying to mimic what a relay would do. for some reasion thou i have two different relays one 5 pin were the centre pin is not used, and the other is a genuin V/P relay which has the four pin confirgeration

My concerns were if there was a fire on board and the loom for keyswitch circuit got damaged and would not switch off the loom, the fuel pump would contine pumping out fuel.

I will digest you brilliant picture and go back out tonight and see what i can do and check.

thank you very much for your time in trying to help me, you are a asset to the site

i will let you know by email what happens."

"Mark, the center pin 87A is o

"Mark, the center pin 87A is only used when you change when the coil is de-energized but you still need to feed a circuit from 30 to 87A. The attached picture will show you the internals of a relay in schematic form.





If you had the problem you describe with a fire onboard, you could also disconnect the main battery switch and you would turn power off everything except perhaps for the bilge pumps, which should be directly connected to the battery. Or you could pull the safety switch at the control (part 11 on the schematic) and that would kill power to the fuel pump.

Look at the schematic from Seloc, which is probably the one your Volvo Penta dealer had in mind. You can always try to upgrade your wiring to reflect that schematic if you feel that's the way to go....

"

"hi el pescador
the relay in

"hi el pescador
the relay in question then must been wrong because the original terminal relay loom block that fits up to the relay have only 4 terminals on the outer and the middle 5 pin is planked off (ie not used).

The original V/P relay is 4 pin and has the same block to fit up to the relay, with the middle one planked off, but i have never been able to find out if they are both the same relays or they differ in some way,i do know thay have to to have a diode across the switch circuit part of the relay.

mark"

"Mark, I think the relay is no

"Mark, I think the relay is not wrong. Since you don't need the middle pin (87A), just so don't connect anything to it. You also may be able to remove that pin if you do it carefully."

Re: "Mark, I think the relay is no

Please hhheeellllllpppppp

It has been a while since this last post. but i have a weird problem and not sure what is going on

battery voltage is 12.63 volts, when ignition is turned to 1 pos dials come on a nd fuel pump the voltage drops to 10.92, discounted pump and still no fault improvement.

ive removed all the purple loom to dash board, traced the purple way back to the main loon connector to the coil.No shorts.

so My fault ????

The purple wire from the start switch when at position 1 has 12.63 volts and all connection from that wire that are jumped up to the dials via legs(dials not connected yet) also have 12.63. reconnected all dials and gauges inc volt dial and all show 12.63v. But as soon as i connected the last purple wire that travels down the boat to the coil and relay the the voltage drops to 10v and all dials then have 10v not 12.63.

if i monitor the battery with a meter the voltage stays at 12.63, but the voltage to the loom as above is 10v

is this right and secondly i would like to see on the volt gauge a correct battery voltage state, how can i get 12+ volts to the gauges and keep 12+continous.